The present invention relates to a substrate processing apparatus that subjects substrates to processing. Substrate processing apparatuses are used to subject various types of substrates such as semiconductor substrates, substrates for liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, and photomasks, and other substrates to various types of processing.
Such a substrate processing apparatus generally subjects a single substrate to a plurality of different types of processing successively (see, for example, JP 2003-3234139). The substrate processing apparatus as described in JP 2003-324139 A includes an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-mentioned substrate processing apparatus, a substrate carried out of the indexer block is transported to the exposure device through the interface block after being subjected to anti-reflection film formation and resist film coating processing in the anti-reflection film processing block and the resist film processing block. After a resist film on the substrate is subjected to exposure processing in the exposure device, the substrate is transported to the development processing block through the interface block. After the resist film on the substrate is subjected to development processing to form a resist pattern thereon in the development processing block, the substrate is transported to the indexer block.
With recent increases in density and integration of devices, making finer resist patterns has become an important problem. Conventional exposure devices have generally performed exposure processing by reduction-projecting reticle patterns on substrates through projection lenses. With such conventional exposure devices, however, the line widths of exposure patterns are determined by the wavelengths of light sources of the exposure devices. Therefore, making finer resist patterns have had limitations.
Therefore, a liquid immersion method is suggested as a projection exposure method allowing for finer exposure patterns (see, for example, WO99/49504 pamphlet). In a projection exposure device according to the WO99/49504 pamphlet, an area between a projection optical system and a substrate is filled with a liquid, resulting in a shorter wavelength of exposure light on a top surface of the substrate. This allows for finer exposure patterns.
In the projection exposure device according to the above-mentioned WO99/49504 pamphlet, however, exposure processing is performed with the substrate and the liquid brought into contact with each other. Therefore, a part of a component of a resist applied on the substrate is eluted in the liquid. The component of the resist eluted in the liquid contaminates a lens of the exposure device.
On the other hand, although the substrate is subjected to various types of film formation processing before the exposure processing, an edge of the substrate may, in some cases, be contaminated in the process of the film formation processing. When the substrate is subjected to the exposure processing with the edge of the substrate thus contaminated, the lens of the exposure device may be contaminated, resulting in a defective dimension and a defective shape of an exposure pattern.